atomant Posted January 9, 2014 Report Share Posted January 9, 2014 The recent thread about the new Vertigo machine and the lack of real innovation in trials machines has led me to think of some ideas that would be pretty cool to overcome some of the issues I know about riding a machine. One of the biggest problems of all time is braking. The latest disc brake technology is the best on offer at the moment and obviously, a big step up from Drum brakes but there are still some major issues:- Disc brake contamination Exposure to damage Lack of consistent control particularly when wet Pad wear and regular maintenance needed I have been toying with a concept and wanted to put it past the very knowledgeable people here to see if this is something worth pursuing. Feel free to rip it to bits or add some constructive comments. Firstly, I am thinking that this would just be for trials machines ONLY because of the slow speeds involved where finesse of braking would be of a serious advantage. Ok, my conceptual idea is to design a hydraulic braking system which is incorporated in the output shaft section of the gearbox which would limit (and stop) the rotational speed of the shaft with almost linear control. The braking would be transfered through the rear chain to the rear wheel. There would be no external braking disc or ancillary equipment. This system would provide the following: No disc brake contamination No external exposure to damage Consistent and linear performance even in the wet No Pad wear - Hydraulic oil would be the only consumable The only obvious downside is that because you are not directly locking the back wheel at the back wheel but braking the wheel through the chain, there will be a little play and movement at standstill. This is aimed at the majority of riders who ride non-stop and want that extra bit of control when going down those banks etc in any conditions who currently either have no brakes or the wheel locks up. Anyway, I know you will tell me what you think. Many thanks Ian Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 9, 2014 Report Share Posted January 9, 2014 Think Duncan McDonald did something like that, defiantly seen it about 25 years ago. Maybe before it's time ! Quote Link to comment Share on other sites More sharing options...
axulsuv Posted January 9, 2014 Report Share Posted January 9, 2014 I use my front brake more than the rear ... ? And would the weight of a extra pump be viable ? Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 9, 2014 Report Share Posted January 9, 2014 I use my front brake more than the rear ... ? And would the weight of a extra pump be viable ? Disconnect your back brake and see how you get on, surprising how much you use it. 1 Quote Link to comment Share on other sites More sharing options...
atomant Posted January 9, 2014 Author Report Share Posted January 9, 2014 I use my front brake more than the rear ... ? And would the weight of a extra pump be viable ? Thanks for replying I think the additional weight would be negligible to be honest. I'm thinking the benefits would outweigh and weight gain and also, this isnt aimed at the bous's of this world, its more like the majority of clubman riders who really wouldnt notice it anyway? Quote Link to comment Share on other sites More sharing options...
atomant Posted January 9, 2014 Author Report Share Posted January 9, 2014 Think Duncan McDonald did something like that, defiantly seen it about 25 years ago. Maybe before it's time ! Thanks for replying Would love to see any details of there are any out there? Quote Link to comment Share on other sites More sharing options...
feetupfun Posted January 9, 2014 Report Share Posted January 9, 2014 the heat produced would need to be rejected so an oil cooler would need to fit in somewhere, maybe a second coil in the engine radiator tank, but it adds a considerable amount of extra weight compared with what is there now The next stage from this would be hydraulic drive to the rear wheel, incorporating braking in the hydraulics (like on a zero-turn lawnmower) Quote Link to comment Share on other sites More sharing options...
atomant Posted January 9, 2014 Author Report Share Posted January 9, 2014 the heat produced would need to be rejected so an oil cooler would need to fit in somewhere, maybe a second coil in the engine radiator tank, but it adds a considerable amount of extra weight compared with what is there now The next stage from this would be hydraulic drive to the rear wheel, incorporating braking in the hydraulics (like on a zero-turn lawnmower) Thanks for replying Yes, heat creation and dissipation is an issue and why I proposed this for a trials machine only because of the low speeds involved. I am certain that the extra weight isn't that significant and to most trials riders, they wouldn't notice it. Hydraulic drive to the back wheel would be interesting incorporating a braking system. All interesting concepts when you get thinking about it Quote Link to comment Share on other sites More sharing options...
biffsgasgas Posted January 9, 2014 Report Share Posted January 9, 2014 (edited) There would be an easier way to do this that would elminate the need for any pump and probably cause minimal weight increase. Use a secondary clutch in the transmission that would engage a second gear. Two different gears engaged at the same time would cause lockup and is sometimes used as a parking brake on manual transmissions. In stead of using the rear brake hydraulics to disengage a clutch you would use it to engage a clutch that would cause a second gear to engage in the transmission. This is currently done with drag race cars and is called a trans brake where they usually engage reverse and first at the same time. When they release the brake it will release the reverse clutch and you are already in first. Clutches are pretty durrable and since they are bathed in the oil that is already there they should outlast brake pads. Clutches would have the same engagement properties as a caliper and pad setup. This would also move the weight of what could be a caliper into the center of the bike. Your idea of keeping the brake out of the enviroment would also be a big benifit. Having the second clutch in the crank case oil shouldn't increase the temprature like a hydraulic pressure system would. Cons would be the durability of the transmission shafts and gears. Another problem would be ability to select a gear that you are not already in. That shouldn't be too hard to overcome especially with a dual shaft system such as gasgas or ossa. I like your idea Atom but a hydrostatic braking system has to involve weight and pressure that may not be the most ideal situation in trials. Driving a hydrostatic pump would also take engine power.... I love my power and would hate to have something effecting it. --Biff Edited January 9, 2014 by biffsgasgas Quote Link to comment Share on other sites More sharing options...
pro sport Posted January 9, 2014 Report Share Posted January 9, 2014 How about an electrical coil inducing a magnetic field through a hub filled with iron filelings ! The field could be increased by applying a higher voltage to increase rotation resistance as pressure is applied to brake lever Only drawback would be if the engine stalls - you would loose your brakes (unless you had a battery back up ) Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted January 9, 2014 Report Share Posted January 9, 2014 Telma do one already great success on ambulances. Atom with your system can you lock up the back and still rev the bike significantly simultaneously? Quote Link to comment Share on other sites More sharing options...
biffsgasgas Posted January 9, 2014 Report Share Posted January 9, 2014 Then you bring this topic up to your fellow automotive engineers and get several more ideas and one possible reason to scrap the whole thing. You could i.Incorporate the rear brake into the chain tensioner. Then the reason for scrapping the whole idea becomes clear. Chains have slack so you would have to worry about that when trying to look like Bou, Caby, or Raga. An electric brake is very easy to make and we use the same concept in locking diffs and AWD transfercases all the time. Its a ball and ramp assembly that rotates next to an elctromagnet. You apply a duty cycle of current into the electro magnet to engage to create a field. That field slows down one half of the rotating assembly. As this slows down the balls work up the ramp causing a clutch to engage. If one element of the clutch pack is held stationary then it will slow down the assembly. The disadvantage is that you have to rotate at least untill the balls roll up the ramp before you get full lockup but it will be full lockup. You could try using variable voltage to create a magnetic field which may make it simpler and more controlable than a dutycycle. --Biff Quote Link to comment Share on other sites More sharing options...
atomant Posted January 9, 2014 Author Report Share Posted January 9, 2014 Telma do one already great success on ambulances. Atom with your system can you lock up the back and still rev the bike significantly simultaneously? Thank you for replying Yes- The output shaft to the rear wheel would be directly braked and therefore with the clutch held in, the engine would rev as usual - If you tried to have the brake on and let the clutch out the engine would stall. Quote Link to comment Share on other sites More sharing options...
atomant Posted January 9, 2014 Author Report Share Posted January 9, 2014 Then you bring this topic up to your fellow automotive engineers and get several more ideas and one possible reason to scrap the whole thing. You could i.Incorporate the rear brake into the chain tensioner. Then the reason for scrapping the whole idea becomes clear. Chains have slack so you would have to worry about that when trying to look like Bou, Caby, or Raga. An electric brake is very easy to make and we use the same concept in locking diffs and AWD transfercases all the time. Its a ball and ramp assembly that rotates next to an elctromagnet. You apply a duty cycle of current into the electro magnet to engage to create a field. That field slows down one half of the rotating assembly. As this slows down the balls work up the ramp causing a clutch to engage. If one element of the clutch pack is held stationary then it will slow down the assembly. The disadvantage is that you have to rotate at least untill the balls roll up the ramp before you get full lockup but it will be full lockup. You could try using variable voltage to create a magnetic field which may make it simpler and more controlable than a dutycycle. --Biff Thanks for replying I did mention in my first post that there would be some play due to the chain but my thinking here is for non-stop trials in a constant forward motion. With hydraulics ( or electromagnetic systems) you can get a virtual linear control on brake tension and therefore this would be beneficial if this wasn't affected by contamination or anything else. I haven't proposed this for the stop trials like indoor as it wouldn't really add anything Quote Link to comment Share on other sites More sharing options...
0007 Posted January 9, 2014 Report Share Posted January 9, 2014 Take it one step further and I'm with you, a hydraulic drive / brake all in one Or a shaft drive and brake all in one Get rid of all the unsprung weight on the wheel, the sprocket and chain and everything You still have lash and chatter issues but there's a big change to the mechanism on the back of the bike Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.